Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint and openWorldHint, so the description is not required to restate safety. It adds useful domain context about the pharmacy's role and what fields are included, though it does not disclose return format or result variability beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences with no filler. The core purpose and scope are front-loaded, and the distinguishing 'cannot prescribe' clarification is placed efficiently at the end.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only listing tool with three optional parameters, fully described in the schema, the description covers the domain context, the UK scope, and the key distinction from clinics. An output schema would have been helpful but is not essential given the description's mention of location, delivery options and rating.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the description does not need to document parameters. It does add light context by mentioning location, delivery options and rating, which loosely maps to query and delivers, but provides no additional parameter semantics beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states exactly what the tool returns: UK pharmacies that dispense medical cannabis, with location, delivery options and rating. It also differentiates from the sibling tools by clarifying the pharmacy role and explicitly noting it cannot prescribe, which separates it from find_clinics and related product/strain tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use this tool: after a clinic has issued a prescription, the user needs a pharmacy to dispense it. It contrasts with prescribing clinics but does not explicitly name alternative tools or state when not to use it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.